After an Ohio coroner issued a dire warning, pot smokers took notice. But is deadly weed laced with a drug 50 times stronger than heroin really out there?

On Monday, a US senator and a local coroner held a depressingly banal press conference on the opioid crisis in Ohio, where death tolls have spiked in part due to hard drugs like heroin being laced with the deadly synthetic opioid fentanyl. The duo repeated talking points that should have been all too familiar to anyone listening, like that the Buckeye State's overdose death rate is nearly double the national average, and Hamilton County—which includes Cincinnati—has it particularly bad.

"We have seen fentanyl mixed with cocaine," said coroner Lakshmi Sammarco. "We have also seen fentanyl mixed with marijuana."

Rumors about laced pot tend to crop up whenever a new drug gains a following. Most of us have heard about dusted drugs or wet weed—though the likelihood of getting tricked into smoking PCP a la Ethan Hawke in Training Day has probably always been slimmer than urban legends might have you believe. As for the allegedly fentanyl-laced cocaine the coroner mentioned, earlier this month, the NYC Health Department did in fact put out a warning about fentanyl-tinged coke in America's largest city; critics countered that there was no way to tell if victims with the two drugs in their systems didn't just consume them separately.

Lloyd Johnston, who runs the US government's massive youth drug survey out of the University of Michigan, told me that while laced weed does have a well-documented history, the chances of finding bud infused with fentanyl seems extremely remote.

Check out the story of one opioid user who beat their dangerous fentanyl habit.

"Documenting the pipe chemistry of fentanyl in leaf material would be a research paper," he told me. "And I don't think it's been done yet."

Fentanyl is no joke—it's 50 times stronger than heroin, which is plenty deadly on its own. But it's important to keep in mind that this isn't the first time we've seen this rumor spread out of Ohio alone. The Painesville Township Fire Department ignited a small panic this February by posting on Facebook about three overdose patients who seemed to be on fentanyl even though they claimed to have only smoked weed. After the post went viral, the department conceded that the patients had probably used drugs besides pot.

And as alarmist—or just plain terrifying—as Sammarco's warning might seem to recreational pot smokers, it left a lot of unanswered questions worthy of scrutiny. Chief among them is how her office might have determined that a body came in with fentanyl-laced marijuana in its system as opposed to marijuana in addition to opioids.

When reached for comment by VICE about her methodology, Sammarco said that her quote had been unfortunately misinterpreted. Her office hasn't seen fentanyl-laced weed at all, she clarified, adding that Rob Portman, the US senator with whom she appeared Monday, told her it had been spotted in northeast Ohio. She told me that she didn't know the senator's source of information.

One possible source of Portman's information could be this local news article, which mentions "false alarms" coming out of northeast Ohio, though no actual, documented cases.

"I don't have anything on that," Portman spokesperson Kevin Smith said when asked if that were the case, before hanging up the phone.

More reassuringly, follow-up reporting by the Cincinnati Enquirer found that no such fentanyl-laced marijuana has been seized by authorities in Hamilton County and that the Cuyahoga County Medical Examiner's office hasn't seen anyone overdose on it, either. In fact, the paper concluded that "no authorities" could back up the story.

But it's easy to understand why this kind of rumor spreads so quickly. Fentanyl is a horrible substance that is being used to cut drugs like heroin, probably because it's cheap and relatively easy to produce. You might say it's an easy way to infuse a sub-par product with a kick—something a shady dealer could one day theoretically use to beef up skunk weed if he or she were a sociopath.

For now, fentanyl seems like a hard-drugs problem.

"Drug dealing has taken a scary twist," former NYPD detective sergeant Joseph Giacalone told me. "We went from the entrepreneurial get 'em hooked and keep 'em coming back to kill them and build a legend as the strongest stuff on the market. 'Chasing the dragon' or trying to find more potent stuff each time has always been a thing for heroin users, but this is a death sentence now."